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Abstract:

A method of binding a network-based service flow is provided. The method
binds a network-based service flow through notification of a terminal by
allowing the terminal to notify a mobile access gateway (MAG) of binding
information of a desired service flow at a specific moment by allowing
intervention of the terminal, and allowing the MAG to again notify a
local mobility anchor (LMA) of corresponding service flow binding
information.

Claims:

1. A method of binding a network-based service flow that binds a service
flow of a mobile node (MN) having a plurality of interfaces in order to
connect to each of heterogeneous networks, the method comprising:
registering mobility binding information of the MN that is connected to a
first mobile access gateway (MAG) of a first network using a first
interface; generating an identifier of the first service flow according
to a predetermined agreement between the first MAG and a local mobility
anchor (LMA) when the first service flow is generated according to a
first service request through the first interface of the MN; updating, by
the first MAG, binding information of the first service flow in order to
notify that a network that provides the first service is the first
network by providing a first proxy binding update (PBU) including the
first service flow identifier to the LMA; including, by the first MAG,
the first service flow identifier in the first message that is provided
to the MN and providing the first message to the MN; and updating, by the
MN, routing information in order to notify that a network that provides
the first service using the first service flow identifier that is grasped
through the first message is the first network.

2. The method of claim 1, further comprising, after the updating routing
information, updating, by a second MAG, mobility binding information of
the MN that is connected to the second MAG of a second network using a
second interface and binding information of the first service flow in
order to notify that a network that provides the first service is a
second network by transmitting a second PBU including the first service
flow ID to the LMA; transmitting, by the second MAG having received a
response of the second PBU, a second message including the first flow
service identifier to the MN; and updating, by the MN, the routing
information in order to notify that a network that provides the first
service using the first service flow identifier that is grasped through
the second message is the second network.

3. The method of claim 2, further comprising, transmitting, by the MN,
the second message including the first service flow identifier to the
second MAG according to a user's request for moving the first service to
the first network; updating, by the second MAG, binding information of
the first service flow in order to notify that a network that provides
the first service is the first network by providing a third PBU including
the first service flow identifier to the LMA; transmitting, by the second
MAG, having received a response of the third PBU, the first message
including the first flow service identifier to the MN; and updating, by
the MN, routing information in order to notify that a network that
provides the first service using the first service flow identifier that
is grasped through the first message is the first network.

4. The method of claim 2, further comprising, updating, by the MN,
routing information in order to notify that a network that provides the
first service using the first service flow identifier is the first
network according to a user's request for moving the first service to the
first network; transmitting, by the MN, the second message including the
first service flow identifier to the second MAG; updating, by the second
MAG, binding information of the first service flow in order to notify
that a network that provides the first service is the first network by
providing a third PBU including the first service flow identifier to the
LMA; and notifying, by the second MAG, having received a response of the
third PBU, the MN of binding information update success of the first
service flow.

5. The method of claim 3, wherein the binding information of the first
service flow comprises the first service flow identifier, the care-of
address (CoA) of the first MAG, and identification information of a
network that provides the first service, and the routing information
comprises the first service flow identifier and identification
information of a network that provides the first service.

6. The method of claim 5, wherein the first message is a router
advertisement (RA) message, and the second message is a router
solicitation (RS) message.

7. The method of claim 6. wherein the first service flow identifier is
included in an option field of the RA message and an option field of the
RS message.

8. A method of binding a network-based service flow that binds a service
flow of an MN having a plurality of interfaces in order to connect to
each of heterogeneous networks, the method comprising: transmitting, by
the MN, having received a first service through a first network, a first
message including a first service flow identifier to a first MAG of a
second network; updating, by the first MAG, binding information of the
first service flow in order to notify that a network that provides the
first service is the second network by providing a PBU including the
first service flow identifier to the LMA; transmitting, by the first MAG,
having received a response of the PBU, a second message including the
first flow service identifier to the MN; and updating, by the MN, routing
information in order to notify that a network that provides the first
service using the first service flow identifier that is grasped through
the second message is the second network.

9. The method of claim 8, wherein the binding information of the first
service flow comprises the first service flow identifier, the CoA of the
first MAG, and identification information of a network that provides the
first service, and the routing information comprises the first service
flow identifier and identification information of a network that provides
the first service.

10. The method of claim 9, wherein the first message is an RS message,
and the second message is an RA message.

11. The method of claim 10, wherein the first service flow identifier is
included in an option field of the RA message and an option field of the
RS message.

12. A method of binding a network-based service flow that binds a service
flow of an MN having a plurality of interfaces in order to connect to
each of heterogeneous networks, the method comprising: updating, by the
MN, having received a first service through a first network, routing
information in order to notify that a network that provides the first
service using the first service flow identifier is the first network
according to a user's request for moving the first service to a second
network; transmitting, by the MN, the first message including the first
service flow identifier to a first MAG of the second network; updating,
by the first MAG, binding information of the first service flow in order
to notify that a network that provides the first service is the second
network by providing a PBU including the first service flow identifier to
the LMA; and notifying, by the first MAG, having received a response of
the PBU, the MN of binding information update success of the first
service flow.

13. The method of claim 12, wherein the binding information of the first
service flow comprises the first service flow identifier, the CoA of the
first MAG, and identification information of a network that provides the
first service, and the routing information comprises the first service
flow identifier and identification information of a network that provides
the first service.

14. The method of claim 13, wherein the first message is an RS message,
and the second message is an RA message.

15. The method of claim 14, wherein the first service flow identifier is
included in an option field of the RA message and an option field of the
RS message.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of Korean
Patent Application No. 10-2009-0128421 filed in the Korean Intellectual
Property Office on Dec. 21, 2009, the entire contents of which are
incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] (a) Field of the Invention

[0003] The present invention relates to a method of managing network-based
mobility. Particularly, the present invention relates to a flow binding
method for binding on a service flow basis of a terminal upon performing
handover of the terminal having a plurality of different network
interfaces.

[0004] (b) Description of the Related Art

[0005] Nowadays, in the Internet engineering task force (IETF), as PMIPv6
is set as a standard, a request for managing IP mobility by network-based
mobility management is increased by mobile communication providers.

[0006] The PMIPv6 provides a mobile access gateway (MAG) function to an
access router of a terminal and a local mobility anchor (LMA) function to
a core network, and thus when the terminal is moved to an area that is
managed by a new MAG, the PMIPv6 describes a procedure in which the
corresponding MAG registers mobility binding information of the terminal
to the LMA. That is, according to the PMIPv6, it is unnecessary for the
terminal to perform any procedure for IP mobility management, and the
terminal manages IP mobility through signaling between the MAG and the
LMA only existing in a network.

[0007] As various kinds of networks are developed and are commercially
available, a plurality of networks are mixed in the same area, and a
terminal (hereinafter, a "multiple interface terminal") having a
plurality of network interfaces is provided such that a heterogeneous
network (i.e., a mixed network) may selectively receive a service from a
specific network.

[0008] In conventional PMIPv6, technology for supporting mobility when
performing handover of a multiple interface terminal is suggested.

[0009] However, while a multiple interface terminal that performs handover
based on the PMIPv6 receives a plurality of services through one network
interface, the multiple interface terminal frequently performs handover,
and in this case, the conventional PMIPv6 does not suggest an alternative
proposal that moves a part of a plurality of service flows in a service
state to another network interface of the multiple interface terminal.

[0010] Therefore, the following documents for solving such a problem are
suggested.

[0014] The first document defines a format of a service flow identifier
option for notifying the LMA of specific service flow information in the
PMIPv6, and suggests that the service flow identifier option is included
in proxy binding update (PBU) and proxy binding acknowledgement (PBA). In
the first document, a time point at which the service flow identifier
option is included in the PBU and is sent to the LMA is determined when
the MAG receives data belonging to a new service flow from any interface
of the terminal. That is, after the terminal is connected to a network
through a new interface, when specific traffic is sent to the MAG through
the interface, the MAG, having received the traffic analyzes the traffic,
then makes a service flow identifier option, and sends the service flow
identifier option together with the PBU when sending the PBU to the LMA.

[0015] However, the first document has a problem that service flow binding
is requested only when data traffic of a new service flow, i.e., uplink
traffic, is sent from the terminal to the MAG, and that service flow
binding cannot be requested when traffic is sent from another
corresponding node to a corresponding node, i.e., when downlink traffic
is sent to the MAG. According to the first document, in a situation where
uplink traffic is temporarily absent after handover, when downlink
traffic arrives in the LMA, the traffic may arrive in an interface that
is not presently intended by the terminal.

[0016] The second document reuses a flow identifier that is suggested in a
draft-ietf-next-flow-binding-03.txt document for supporting a service
flow binding service of MIPv6, which is an existing host-based mobility
management protocol, without newly determining a format of a service flow
identifier option. However, according to the second document, in order to
cause service flow handover, a flow binding policy for a specific service
of the terminal depends on a profile of the terminal or a provider's
policy. That is, a binding method for a specific flow is stored in a
database that manages various information of the terminal, and service
flow binding is started based on the stored information.

[0017] Therefore, the second document has a problem that a user who
actually uses a terminal starts service flow binding with reference to
only previously stored static information regardless of a desired
preference at that moment. For example, a previously stored profile
describes that VolP service traffic should be exchanged through a WLAN
interface, but a scenario in which the user should use a VolP service
using a 3GPP interface at a specific moment for any reason cannot be
supported.

[0018] The third document defines a flow handover request (FHRQ) and a
flow handover reply (FHRP), which are separate signaling messages for
service flow handover, and does not define a separate identifier for
identifying a service flow, and uses a method of putting an IP address
and a port number for identifying a flow as an option of the above two
messages.

[0019] Therefore, in the third document, because a method of causing
handover of the service flow still depends on a profile of the terminal
or a provider's policy, as in the second document, the third document has
the same problem that is described for the second document.

[0020] The above information disclosed in this Background section is only
for enhancement of understanding of the background of the invention and
therefore it may contain information that does not form the prior art
that is already known in this country to a person of ordinary skill in
the art.

SUMMARY OF THE INVENTION

[0021] The present invention has been made in an effort to provide a
method of binding a network-based service flow through notification of a
terminal.

[0022] Also, the present invention has been made in an effort to further
provide a method of binding a network-based service flow through
notification of a terminal having advantages of allowing service flow
binding in which an intention of the terminal is accurately reflected, as
the terminal directly controls service flow binding.

[0023] An exemplary embodiment of the present invention provides a method
of binding a network-based service flow that binds a service flow of a
mobile node (MN) having a plurality of interfaces in order to connect to
each of heterogeneous networks. The method includes: registering mobility
binding information of the MN that is connected to a first mobile access
gateway (MAG) of a first network using a first interface; generating an
identifier of a first service flow according to a predetermined agreement
between the first MAG and a local mobility anchor (LMA) when the first
service flow is generated according to a first service request through
the first interface of the MN; updating, by the first MAG, binding
information of the first service flow in order to notify that a network
that provides the first service is a first network by providing a first
proxy binding update (PBU) including the first service flow identifier to
the LMA; including, by the first MAG, the first service flow identifier
in a first message that is provided to the MN and providing the first
message to the MN; and updating, by the MN, routing information in order
to notify that a network that provides the first service using the first
service flow identifier that is grasped through the first message is the
first network.

[0024] Another embodiment of the present invention provides a method of
binding a network-based service flow that binds a service flow of an MN
having a plurality of interfaces in order to connect to each of
heterogeneous networks. The method includes: transmitting, by the MN,
having received a first service through a first network, a first message
including a first service flow identifier to a first MAG of a second
network; updating, by the first MAG, binding information of the first
service flow in order to notify that a network that provides the first
service is the second network by providing a PBU including the first
service flow identifier to the LMA; transmitting, by the first MAG,
having received a response of the PBU, a second message including the
first flow service identifier to the MN; and updating, by the MN, routing
information in order to notify that a network that provides the first
service using the first service flow identifier that is grasped through
the second message is the second network.

[0025] Yet another embodiment of the present invention provides a method
of binding a network-based service flow that binds a service flow of an
MN having a plurality of interfaces in order to connect to each of
heterogeneous networks. The method includes: updating, by the MN, having
received a first service through a first network, routing information in
order to notify that a network that provides the first service using the
first service flow identifier is the first network according to a user's
request for moving the first service to a second network; transmitting,
by the MN, the first message including the first service flow identifier
to a first MAG of the second network; updating, by the first MAG, binding
information of the first service flow in order to notify that a network
that provides the first service is the second network by providing a PBU
including the first service flow identifier to an LMA; and notifying, by
the first MAG, having received a response of the PBU, the MN of binding
information update success of the first service flow.

[0027] FIG. 2 is a data flowchart illustrating a method of binding a
network-based service flow according to a first exemplary embodiment of
the present invention.

[0028] FIG. 3 is a service flow state diagram before handover for
additionally describing a method of binding a network-based service flow
according to the first exemplary embodiment of the present invention that
is described with reference to FIG. 2.

[0029] FIG. 4 is a service flow state diagram after handover for
additionally describing a method of binding a network-based service flow
according to the first exemplary embodiment of the present invention that
is described with reference to FIG. 2.

[0030]FIG. 5 is a data flowchart illustrating a method of binding a
network-based service flow according to a second exemplary embodiment of
the present invention.

[0031] FIG. 6 is a service flow state diagram for additionally describing
a method of binding a network-based service flow according to the second
exemplary embodiment of the present invention that is described with
reference to FIG. 5.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In the following detailed description, only certain exemplary
embodiments of the present invention have been shown and described,
simply by way of illustration. As those skilled in the art would realize,
the described embodiments may be modified in various different ways, all
without departing from the spirit or scope of the present invention.
Accordingly, the drawings and description are to be regarded as
illustrative in nature and not restrictive. Like reference numerals
designate like elements throughout the specification.

[0033] Now, a method of binding a network-based service flow through
notification of an integrated terminal according to an exemplary
embodiment of the present invention will be described in detail with
reference to the drawings.

[0034] In the exemplary embodiment of the present invention, the method of
binding a network-based service flow is performed, for example, in a
proxy mobile Internet protocol version 6 (PMIPv6) domain, but is not
restricted thereto.

[0035] Before the description, in the present invention, a method of
binding a service flow between a mobile access gateway (MAG) and a local
mobility anchor (LMA) while basically following a network-based service
flow binding policy is used, as in an existing method that is submitted
to an Internet engineering task force (IETF). In basic information that
manages a service flow between the MAG and the LMA, an identifier for a
service flow is used, as in a first document and a second document that
are submitted to the IETF, but which type of service flow identifier is
used and how to generate the identifier use a method to be standardized
later in the IETF.

[0037] As shown in FIG. 1, a heterogeneous protocol mixed network to which
an exemplary embodiment of the present invention is applied is a network
in which a high-speed downlink packet access (HSDPA) network, which is
one of a WiBro network and a 3rd generation (3G) network is mixed. In
this case, the WiBro network and the HSDPA network may be in an
overlapped form, in an independent form, or in a partially overlapped
form.

[0038] An ACR of the WiBro network and a gateway GPRS support node (GGSN)
of the HSDPA network perform a mobile access gateway (MAG) function for
providing IP mobility, and a device having a local mobility anchor (LMA)
function is provided in a core network.

[0039] A mobile node (MN) is a multiple interface terminal, and includes a
WiBro interface (not shown) for allowing communication to be performed
through the WiBro network and an HSDPA interface (not shown) for allowing
communication to be performed through the HSDPA network.

[0040] Such an MN may receive a service by connecting to the WiBro network
through the WiBro interface, may receive a service by connecting to the
HSDPA network through the HSDPA interface, or may receive a service from
the WiBro network and the HSDPA network through the WiBro interface and
the HDSPA interface, respectively.

[0041] When a service flow is generated according to a service request of
the MN, the MAG and the LMA generate a service flow ID for a service flow
that is generated by a predetermined agreement thereof.

[0042] In the exemplary embodiment of the present invention, the network
and the MN share the generated service flow ID, and thus upon performing
handover of the MN, the service flow ID is used for moving some or all of
a service flow to an interface of the handover network.

[0043] Movement of the service flow binds a service flow ID between the
MAG and the LMA and is synchronized with binding of the service flow ID
and thus an interface for a corresponding service flow is changed even in
the MN. Specifically, in the exemplary embodiment of the present
invention, the

[0044] MAG requests binding of a service flow ID to the LMA and the LMA
accepts a request for binding of the service flow ID, and thus binding of
the service flow ID is performed, and the MAG notifies the MN of the
generated service flow ID and the MN changes an interface, thereby
synchronizing the change of the service flow interface.

[0045] In this case, a situation of causing binding of a service flow
occurs based on a profile of the MN or a provider's policy.

[0046] Accordingly, when the MN receives the service flow ID from the MAG,
the MN has a first function portion (not shown) that registers the
service flow ID to a session management table to correspond to a
corresponding interface.

[0047] The MN grasps a service flow using (i.e., registered) on an
interface basis through a service flow ID in an application session
management table, and includes a service flow transformer portion (not
shown) that can map a specific service flow to another interface
according to a user's request.

[0048] The service flow transformer portion can select that the user is to
receive a service through which interface in a specific service flow
according to the user's preference. For example, when the MN receives a
first service through the WiBro interface and receives a second service
through the 3G interface, the user can receive the first service through
the 3G interface and the second service through the WiBro interface using
the service flow transformer portion.

[0049] A service flow moving function between active interfaces of the
service flow transformer portion is a function of dynamically moving some
or all of the service flow as the user wants between activated interfaces
so that the user may presently give and receive normal traffic.

[0050] When an interface corresponding to the service is changed, the
service flow transformer portion matches and registers a service flow ID
of a corresponding service that is registered to the session management
table to the changed interface.

[0051] Hereinafter, a method of binding a network-based service flow
according to the first exemplary embodiment of the present invention will
be described with reference to FIGS. 2 to 4.

[0052] Before the description, in the first exemplary embodiment of the
present invention, handover of the MN is performed from the WiBro network
to the 3G network (i.e., a HSDPA network), and in this case, a service
flow ID that is newly generated in the MAG is used to notify using a
router advertisement (RA) message in the network (i.e., MAG).

[0053] FIG. 2 is a data flowchart illustrating a method of binding a
network-based service flow according to a first exemplary embodiment of
the present invention, and FIG. 3 is a service flow state diagram before
handover for additionally describing a method of binding a network-based
service flow according to the first exemplary embodiment of the present
invention that is described with reference to FIG. 2. FIG. 4 is a service
flow state diagram after handover for additionally describing a method of
binding a network-based service flow according to the first exemplary
embodiment of the present invention that is described with reference to
FIG. 2.

[0054] As shown in FIG. 2, when the MN is connected to an MAG
(hereinafter, referred to as an "MAG_old") of the WiBro network through
the WiBro interface (S201), the MAG_old acquires an identifier and a
profile of the MN, generates a terminal connection event trigger, and
requests a proxy binding update (PBU) from the LMA.

[0055] The LMA grasps routing information (e.g., routing table and rule)
by accepting a PBU request of the MAG_old, and sets a binding cache entry
(BCE).

[0056] Hereinafter, the BCE is referred to as a service binding table T1.
The service binding table T1 further includes general information for
binding, i.e., information for managing a service flow together with
routing information of the MN.

[0057] That is, the service binding table T1 includes a home network
prefix (HNP), an MN-ID, which is an identifier of the MN, a care-of
address (CoA), which is an address of the MAG old to which the MN is
connected, and an interface representing a flow ID, which is an ID of a
service flow in which the MN is using and a network in which a
corresponding service flow is provided, as shown in FIGS. 3 and 4. The
binding table T1 may further include an IP representing an IP address of
a correspondent node (CN), a Port representing a service port, and a
Trans representing a transmission protocol.

[0058] Thereafter, the LMA transmits proxy binding acknowledge (PBA) to
the MAG_old as a response to the PBU (S202).

[0059] The MAG_old checks the PBA of the LMA, generates a bi-directional
tunnel between the LMAS, and sets routing information (e.g., CoA,
interface, IP, Flow ID, and Trans) corresponding to the MN (S203).

[0060] When the MN first connects to the WiBro network, the MN transmits a
router solicitation (RS) message to the MAG_old (S204), and the MAG_old
transmits a unicast type RA message as a response to the RS message to
the MN, thereby notifying the MN of its existence (S205).

[0061] In this way, when the tunnel is generated, a subscriber performs a
service that the subscriber wants through the MN. When the subscriber
tries to perform communication while watching a television, the
subscriber receives an IPTV service by requesting the IPTV service
through the MN and requests a communication service, or receives a
communication service by requesting the communication service and
requests the IPTV service.

[0062] In the following description, for convenience of description, an
IPTV service is referred to as a first service and a communication
service (i.e., a VolP service) is referred to as a second service, and a
service providing procedure for each of two services (i.e., the first
service and the second service) should be sequentially described, but
because the service providing procedures are the same, a service
providing procedure will be described.

[0063] When the MN requests the first service and the second service by a
user request (S206), the MAG_old transmits a service request message to
each service server (not shown) that provides a corresponding service
(S207).

[0064] Accordingly, a session for the services is set between the service
server and the MN (S208), and a service flow between the MN H the MAG_old
H the service server is formed through a predetermined session.

[0065] As the service flows are formed, IDS (fowl ID and flow2 ID) for
first and second service flows, respectively, are generated between the
MAG_old and the LMA (S209), and the MAG_old includes the generated
service flow ID in an option field of the RA message and transmits the RA
message to the MN (S210).

[0066] In this case, information that is included in an option field of
the RA message that is transmitted from the MAG_old to the MN may include
an IP address, a port number, and a transport protocol name of a
correspondent node (CN) together with a service flow ID.

[0067] When the MN receives the service flow ID, the MN matches a service
flow ID that is received in a stored session management table T2 to a
corresponding interface and registers the service flow ID (S211).

[0068] In this case, the session management table T2 includes a flow ID,
which is an ID of a using service flow and an interface representing an
interface in charge of the corresponding service flow, as shown in FIGS.
3 and 4. The session management table T2 may further include an IP
representing an IP address of a correspondent node (CN), an interface
representing a network in which a corresponding service flow is provided,
a Port representing a service port, and a Trans representing a
transmission protocol.

[0069] When a session is set through the process S208, the MAG_old
transmits the PBU (including a service flow ID) requesting binding update
for the generated service flow ID to the LMA (S212).

[0070] Accordingly, the LMA updates (or generates) the service binding
table T1 for the MN (S213), as shown in FIG. 3.

[0071] When binding update for a service flow is complete, the LMA
transmits the PBA to the MAG_old (S214).

[0072] Here, the process S211 of transmitting an RA message including a
service flow ID may be performed after the process S214.

[0073] Therefore, the MN receives an IPTV service, which is the first
service and a communication service, which is the second service from the
WiBro network through the WiBro interface. The MN and the LMA share the
same information about a service flow through processes S210, S211, and
S213.

[0074] In this state, when a situation in which the MN performs handover
to the HSDPA network, which is a 3G network, occurs, a 3G interface of
the MN requests handover by connecting to an MAG_new (S215).

[0075] The MAG_new, having received a handover connection of the MN,
determines to provide a second service (communication service) of the MN
through the 3G network by performing an operation according to management
(follows a standard of IETT to be set later) for a service flow ID
together with the LMA.

[0076] Accordingly, when requesting the proxy binding update (PBU) to the
LMA, the MAG_new includes the second service flow ID in the PBU and
transmits the PBU (S216).

[0077] Therefore, the LMA grasps routing information by accepting a PBU
request of the MAG_new and updates binding, and updates service binding
through the second service flow ID (flow2 ID) that is included in the PBU
(S217).

[0078] Here, by updating service binding, matching of the second service
flow ID (flow2 ID) is varied from the WiBro interface to the 3G interface
in the service binding table T1, as shown in FIG. 4.

[0079] When binding update is complete, the LMA transmits the PBA to the
MAG_new (S218), and the MAG_new checks the PBA of the LMA, generates a
bi-directional tunnel between the LMAS, and sets routing information
(e.g., CoA, Interface, IP, Flow ID, and Trans) corresponding to the MN
(S219).

[0080] The MAG_new includes the second service flow ID in the RA message
in order to notify a change of the second service flow, and transmits the
RA message to the MN (S220). Therefore, the MN checks that the second
service flow ID is included in the RA message that is received through
the 3G interface, and thus updates routing information of the second
service flow that changes matching of the second service flow ID that is
registered in a session management table to the 3G interface (S221).

[0081] Hereinafter, a method of binding a network-based service flow
according to a second exemplary embodiment of the present invention will
be described with reference to FIGS. 5 and 6.

[0082] The second exemplary embodiment of the present invention describes
a case of binding a corresponding service flow by synchronizing the
network and the MN to correspond to a case where the user requests to
receive a service through a specific service flow from a presently
connected network through another heterogeneous network.

[0083] In the second exemplary embodiment of the present invention, a
method of binding a service flow is applied in an MN state after service
flow binding after handover that is described with reference to FIG. 4.
However, a method of binding a service flow according to the second
exemplary embodiment of the present invention can be applied before
handover, and the application can be easily executed by a person of
ordinary skill in the art through the following description and therefore
a detailed description thereof will be omitted.

[0084] As shown in FIG. 3, the MN provides the first and second services
through the WiBro interface, after performing handover, the second
service is provided through the 3G interface, and the first service is
provided through the WiBro interface (S501 to S513), as shown in FIG. 4.

[0085] In this state, the user instructs to move the first service
receiving through the WiBro interface to the 3G network interface.

[0086] Accordingly, a service flow transformer portion of the MN
determines an interface change event for the first service flow (S514).

[0087] The service flow transformer portion of the MN moves and maps the
first service flow that is mapped to the WiBro interface to the 3G
interface and inactivates the WiBro interface. Further, the service flow
transformer portion of the MN changes an interface of routing information
about the first service flow ID (flow1 ID) that is registered to the
session management table to the 3G interface (S515).

[0088] Thereafter, the MN includes the first service flow ID (flow1 ID) in
an option field of an RS message, which is a message that is set as a
PMIPv6 standard and that transmits from the MN to the MAG and transmits
the RS message to the MAG_new (i.e., the MAG of the 3G network), and
requests binding of the first service flow (S516). When the MAG_new
receives the RS message in which the first service flow ID (flow1 ID) is
included, the MAG_new transmits the PBU in which the first service flow
ID (flow1 ID) is included to the LMA (S517).

[0089] The LMA grasps the first service flow ID that is included in the
PBU and accepts a PBU request of the MAG_new, thereby updating a service
binding table through the first service flow ID (flow1 ID) that is
included in the PBU (S518), as shown in FIG. 6.

[0090] In this case, by grasping routing information that is included in
the PBU, the LMA determines whether CoA is equal to the previously stored
CoA, and if CoA is equal to the previously stored CoA, the LMA updates
service flow binding that allows an interface corresponding to the first
service flow ID (flow1

[0091] ID) to be 3G, and if CoA is not equal to the previously stored CoA,
the LMA updates binding according to handover. The present invention may
not perform a comparison process of CoA by including a separate
identifier that instructs service flow binding in the PBU.

[0092] When update of service flow binding is complete, the LMA transmits
the PBA to the MAG_new (S519).

[0093] The MAG_new knows that binding for the first service flow is
updated with the received PBA, sends an RA message including the first
service flow ID (flow1 ID) to the MN, and notifies the MN whether update
of service flow binding is succeed.

[0094] In the foregoing exemplary embodiment, it is described that a
binding update process (S515) in a session management table according to
an interface change for the first service flow is performed before
binding update in the LMA, but it is not limited thereto. For example, in
an exemplary embodiment of the present invention, when an RA message that
notifies update of service flow binding is received from the MAG_new, the
process S515 may be performed.

[0095] According to the present invention, the MN directly controls
service flow binding in real time when a user wants, thereby performing
service flow binding in which an intention of the MN is accurately
reflected.

[0096] Further, in the present invention, when the MN is set to perform
communication with a new interface for a specific service flow using a
service flow moving function between active interfaces, although downlink
traffic of a service flow that is transferred from a correspondent node
(ON) to the MN first arrives in the LMA before uplink traffic of a
corresponding service flow advancing from the MN to the network occurs,
the MN can receive uplink traffic in the intended new interface.

[0097] Further, in the present invention, compatibility can be sustained
at 100% based on a network-based service flow binding control method to
be standardized in IETF.

[0098] Further, in the present invention, an existing message is used to
the maximum without defining a new message between the MAG and the MN.

[0099] An exemplary embodiment of the present invention may be not only
embodied through the above-described apparatus and method, but may also
be embodied through a program that realizes a function corresponding to a
configuration of exemplary embodiments of the present invention or a
recording medium on which the program is recorded and can be easily
embodied by a person of ordinary skill in the art from a description of
the foregoing exemplary embodiment.

[0100] While this invention has been described in connection with what is
presently considered to be practical exemplary embodiments, it is to be
understood that the invention is not limited to the disclosed
embodiments, but, on the contrary, is intended to cover various
modifications and equivalent arrangements included within the spirit and
scope of the appended claims.

Patent applications by Byungjun Ahn, Daejeon KR

Patent applications by Ki Cheol Jeon, Daejeon KR

Patent applications by Yoon Young An, Daejeon KR

Patent applications by Center for University-Industry Corporation

Patent applications by Electronics and Telecommunications Research Institute